30 pin simm 8 and 9 chip

[exxos]

Hi all,

I brought some 9chip 30 pin simms by mistake a long time ago, thewe are
parity types, is it possible to convert them to the 8chip non-parity types
with some mods or something ?

thanks
chris

 

[Harry Conover]

"exxos" <chris@home.co.uk> wrote in message news:<402e2b00$0$6846$cc9e4d1f@news.dial.pipex.com>...

Hi all,

I brought some 9chip 30 pin simms by mistake a long time ago, thewe are
parity types, is it possible to convert them to the 8chip non-parity types
with some mods or something ?

Not easily. They are also rather obsolete, so I would just consign
them to the trash can.

Harry C.

 

[Zak]

Harry Conover wrote:

"exxos" <chris@home.co.uk> wrote in message news:<402e2b00$0$6846$cc9e4d1f@news.dial.pipex.com>...

Hi all,

I brought some 9chip 30 pin simms by mistake a long time ago, thewe are
parity types, is it possible to convert them to the 8chip non-parity types
with some mods or something ?


Not easily. They are also rather obsolete, so I would just consign
them to the trash can.

Well, if you need 30 pin "8 chip" ones (I presume he needs 8 bits) I
guess he can just use the 9 chip 30 pin banks - the extra chip will
simple not be used. Obsolete or not doesn't come into the equation.

A bigger point is the type - FP or EDO. This matters in some
applications, though some FP apps take EDO (other way around is
sometimes provided for compatibility).

So, for the OP: there is no need to convert, as long as the other specs
are okay.


Thomas

 

[Michael Black]

Zak (spam@jutezak.invalid) writes:

Harry Conover wrote:
"exxos" <chris@home.co.uk> wrote in message news:<402e2b00$0$6846$cc9e4d1f@news.dial.pipex.com>...

Hi all,

I brought some 9chip 30 pin simms by mistake a long time ago, thewe are
parity types, is it possible to convert them to the 8chip non-parity types
with some mods or something ?


Not easily. They are also rather obsolete, so I would just consign
them to the trash can.

Well, if you need 30 pin "8 chip" ones (I presume he needs 8 bits) I
guess he can just use the 9 chip 30 pin banks - the extra chip will
simple not be used. Obsolete or not doesn't come into the equation.

A bigger point is the type - FP or EDO. This matters in some
applications, though some FP apps take EDO (other way around is
sometimes provided for compatibility).

So, for the OP: there is no need to convert, as long as the other specs
are okay.


Thomas

It almost seemed like a gimmick. Not the parity, but when Macintoshes
did not use parity, one could sort of mislead the buyer towards a more
expensive (because it was less common) non-parity SIMM. I remember once
I told someone who had posted in the local buy and sell newsgroup looking
for "Mac memory" that any SIMMs would work, and he was quite pleasantly
surprised to hear that.

The parity bit is of course just another bit of memory on the board,
and if the thing it's plugged into doesn't make use of it, it can't
tell whether or not there is parity on the SIMM.

Of course, if you do need parity, and the SIMM has none, that would
cause a problem.

The one thing that might be an issue is the density of the RAM
on the SIMM. I once got some RAM off a junk motherboard, and soldered
them to some junk 256K SIMMs that someone had given me (taking off
the RAM first), and thought I'd gotten cheap 1M SIMMs (at a time
when they were still relatively expensive). I put them in my Mac
Plus, and they worked fine. But when I left it without doing anything,
it would crash when I moved the mouse. Reading up, it turned out
that Mac could not use SIMMs with ICs that were four bits wide, but
needed RAM that were 1 bit wide. It wasn't getting refreshed in the Mac,
which explained why it worked so long as I kept doing things on the Mac,
but bombed if I let it sit there for a while. But this issue would
only come up in very specific cases.

Michael